The winter of 2013-2014 was one of the coldest in twenty years in Europe and North America. How is this interpreted in a generally warming world? As Randy Cerveny explains, these cold snaps used to happen every other year. Now it is decades between these events. While extremes such as the hottest temperature or the strongest winds are not being exceeded yet, local record temperatures and average temperatures are rising everywhere.

Transcript

Robyn Williams: And this is The Science Show on RN, where a bigger wind is blowing, a world record wind, and recording is important. Sometimes winds are so strong they just wreck the apparatus. Randy Cerveny and his panel want exact records. He's President's Professor of Geographical Sciences at Arizona State University in Phoenix.

Randy Cerveny: Well, we have set up this panel that investigates all these kind of claims. Until recently it was at a place called Mount Washington Observatory in New Hampshire. The winds were on the order of 231 miles per hour there, and that was recorded by people back in the 1930s. My committee that we put together just a couple of years ago determined that there was a new location, and it's off the coast of Australia, where the winds have actually reached on the order of 253 miles per hour or somewhere around 113 metres per second. So extremely strong winds. That was associated with a tropical cyclone that hit that area back in 1996.

Robyn Williams: Is that likely to be the biggest, the fastest wind ever recorded?

Randy Cerveny: The key word there was 'recorded'. We have had estimates of winds inside tornadoes, for example, that can exceed 300 miles an hour, but we've never had an instrument that has actually survived that kind of an encounter, that's what made this event off the coast of Australia so interesting is that it was on a small island, they had a remote weather station, and afterwards when the oil workers that were associated with this particular area came back they found that the actual instrument, although quite damaged, was still operating and it could be tested and found to have been working accurately. So it set the new record for highest recorded wind that we ever seen on the planet.

Robyn Williams: We've had a succession of temperatures in Australia, in Adelaide, 47 Celcius, that was a week in which they were well into the 40s all the time. What's the hottest recording made as far as you're concerned?

Randy Cerveny: The hottest temperature recorded on the planet we determined to be at a place called Death Valley in California where the temperature actually got up to 56.2 Celsius, 134 Fahrenheit.

Robyn Williams: That's formidable, isn't it.

Randy Cerveny: I've been in Death Valley when it has been approaching 50 degrees and that was enough for me actually.

Robyn Williams: Yes, it's hard to live with. Why are you coordinating these extreme claims? What's the point?

Randy Cerveny: Well, until recently the only places where we had this kind of information was from private sources like the Guinness Book of World Records, but as we are getting into a time where climate change becomes really critical we need to know what are the extremes of this planet so that we can determine are we exceeding them, are we reaching them more often. So we had to set up a viable set of scientists to examine exactly what those extremes have been on our planet and to verify any new ones. The group that decided to take on that challenge is something that's called the World Meteorological Organisation, it's kind of linked in with the United Nations but it's the affiliation of all the national weather services around the entire world.

Robyn Williams: It is our impression that there is more extreme weather around now, just by listening to the news and reading the newspapers. Is that the trend you're finding as well?

Randy Cerveny: Well, actually the extremes, the absolute extremes haven't changed that much. The hottest temperature on this planet, that temperature I was talking about in Death Valley, was actually recorded all the way back in 1913. What we're finding is that the average has been moving upward, both in terms of the lowest temperatures that we record on this planet and the average temperatures. But the highest extremes have so far remained constant. We are probably going to see over the next few decades more of those records following, but as of this time those records haven't reached the extremes yet.

Robyn Williams: Okay, the records have not been exceeded necessarily, but the number of extreme events, are you getting an impression that the number of extreme events is going up?

Randy Cerveny: Yes, that has been the case, the occurrence of more records being set at individual locations around the world has definitely been picking up.

Robyn Williams: One thing that has been consistent over the last two, three, four years in North America and in Europe is that it's getting very, very cold. The freezing winters are much colder than they seem to have been before. There's been some suggestion it's because of the vortex, the way the winds are now affected by climate change and dipping down like they didn't used to. Is that the impression you have?

Randy Cerveny: Well, actually the interesting thing, Europe and particularly the east coast of the United States this winter was one of the coldest that we have on record, but what's interesting is actually the kind of flip side of that coin. We haven't had many of those in recent years. These cold snaps like we had in the winter of 2013 up here in the States hasn't been seen for 20 or 30 years. They used to be happening every other year. Now we are getting them separated by decades. That's probably an indication that actually climate is indeed changing.

Robyn Williams: How would you adduce that as a fingerprint of climate change?

Randy Cerveny: Well, the frequency of cold waves is going to be associated, as you were mentioning, with something that is called the circumpolar vortex, it's this ring of air that encircles the North Pole and it keeps the polar air locked up around the North Pole, and it kind of wobbles over time. What's happened is that while we did have an intense wobble over the eastern part of the United States this year, that has not been the situation that we've had over recent years. So consequently some climate scientists are suggesting that the frequency of these kind of occurrences, if they are going down, is an indication of a warming world.

Robyn Williams:And it's also a windy world, and that world record wind you heard about was measured, I'm told, just off Broome in Western Australia. Randy Cerveny is President's Professor of Geographical Sciences at Arizona State University in Phoenix.

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Comments (1)

Doomsday Chook :

25 May 2014 7:15:56pm

Try explaining this to the Great Leader in Canberra, his cabinet, his big business backers, the rightwing propaganda-tanks like the IPA, the insane ideologues of the Murdoch apparatus or the rabble of Dunning-Krugerites who voted for him (now feeling the lash of Budget cuts). I heard some worthy speaking of the leadership in Beijing recently. When asked if there was a denialist claque amongst the Chinese leadership, he had a little snigger, and observed that Chinese leaders rise according to their talent and intelligence and many are engineers and scientists. Denialism, in the face of the near unanimous scientific consensus is for them, a bewildering, mainly Anglosphere psychosis. Another field in which Austraya is truly 'world-class'- idiocy.